Public-Access Defibrillation Leads to Better Neurological Outcome Even in Patients Without Pre-Hospital Return of Spontaneous Circulation: A Population-Based Cohort Study

Abstract

Background: The dissemination of public-access automated external defibrillators has improved outcomes in patients with out-of-hospital cardiac arrest (OHCA) who have a shockable initial rhythm. However, more than 80% of public-access defibrillation attempts do not result in sustained return of spontaneous circulation (ROSC) in OHCA patients with a shockable rhythm before emergency medical service (EMS) contact. Hence, we wish to focus on outcomes of patients with bystander-witnessed OHCA and a shockable rhythm who did not achieve ROSC after public-access defibrillation. Methods: From a nationwide, prospective, population-based registry of 1,299,784 OHCA patients in Japan, we identified 115,406 patients from 2005 through 2015 with bystander-witnessed cardiac arrests of presumed cardiac origin in whom cardiopulmonary resuscitation (CPR) was attempted. The primary outcome measure was favourable neurological outcome (Cerebral Performance Category of 1 or 2) at 1 month. Findings: Of 28,019 patients with bystander-witnessed OHCA and a shockable rhythm, 2,242 patients (8%) who did not achieve ROSC with public-access defibrillation and 25,087 patients (92%) who did not achieve ROSC without public-access defibrillation before EMS contact. The rate of favourable neurological outcome was significantly higher in the group with versus without public-access defibrillation (38% [845/2,242] vs. 23% [5,676/25,087], adjusted odds ratio after propensity score matching, 1·45; 95% confidence interval, 1·24 to 1·69, P<0·0001). Interpretation: Public-access defibrillation before EMS arrival is associated with better neurological outcomes in OHCA patients with a shockable rhythm, even those did not achieve ROSC at time of public-access defibrillation. (the University Hospital Medical Information Network Clinical Trials Registry number, UMI09918.) Funding: There was no funding source for this study. Declaration of Interest: We declare no conflict of interest. Ethical Approval: A subcommittee of resuscitation science in the Japanese Circulation Society was provided with registry data after following prescribed governmental legal procedures and approval by the ethics committee of National Cerebral and Cardiovascular Centre. In this registry study, the requirement of written informed consent was waived. Researchers analyzed only deidentified (anonymized) data. It was registered on the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMI09918).